Last Halloween, Caleb Dawson, 18, organized a different kind of trick-or-treating experience. Instead of candy, he and 350 kids from 19 schools near Seattle collected 12,562 pounds of supplies for local food banks. He and classmates at Federal Way High School have also “adopted” a village in Sierra Leone, raising money to help alleviate hunger and support education there.

His school has been his community-service hub, but on Wednesday, Dawson will play hooky. He’s going to We Day at Seattle’s Key Arena, where he and 15,000 other students will have their commitment to doing good reinforced by Jennifer Hudson, who will sing and talk about her campaign to end violence, and basketball great Magic Johnson, who will speak about the battle against HIV-AIDS. It’s the first time the Canadian-based event will be held in the U.S., and Nelly Furtado, Martin Sheen and Martin Luther King III will be there too — all part of a worldwide effort led by the Free the Children charity to inspire kids to make the world a better place.

What can a bunch of kids do? A lot, it turns out. The students attending the event have already raised money for a well and water purification system in Ethiopia, participated in the March of Dimes Walk for Babies and volunteered at a Christmas party for foster children.

We Day is the brainchild of Canadian Craig Kielburger, whose commitment to community service began in 1995 when, at 12 years old, he read about a Pakistani child who was sold into slavery and later killed for speaking out. Appalled, he rallied 11 of his seventh-grade classmates to help him host car washes and bake sales to raise money for children in danger. Kielburger and his brother now run Free the Children, which has hosted We Day in Canada for the past six years, and with its first foray into the U.S. this year, they hope to make it an annual event here as well. “When we started in Canada, youth were the least likely group to volunteer,” says Kielburger. “Today they’re the most likely. We’re trying to inspire a generation of kids to care.”

With 3.3 million followers, We Day is one of the largest charities on Facebook. While experts — and parents — wring their hands over this generation’s sense of entitlement, a significant portion of children are exploiting the instant and wide-ranging connections they build on Facebook to raise awareness of issues that matter to them. It’s not unusual, for example, for students to turn online in order to right wrongs — such as starting petitions on Change.org, as 13-year-old McKenna Pope did in December by urging toy manufacturer Hasbro to make its iconic Easy-Bake Oven in gender-neutral colors. She won them over.

Thousands of youngsters every day are making equally meaningful efforts to better their local community, even without the national headlines. So We Day, with its glitz and superstars, is essentially a big pep rally for these dedicated volunteers, a way to congratulate and celebrate their selflessness and spur them on to do more. Since the event launched, middle-school and high-school students have contributed more than 5 million volunteer hours and raised $26 million for 900 different charities and causes.

Students can’t buy tickets to the six-hour event; they have to earn them by getting involved through their schools in one local and one global service project over the course of an academic year. (The event will be streamed live on Q13Fox.com beginning at 9:30 a.m. PST.) Schools receive educational resources that help teachers guide students into taking action on any number of issues including homelessness, women’s rights, hunger and poverty.

Kielburger makes the case that a spirit of volunteerism is critical to a good education. “We’re a one-stop shop that advocates systematic service learning in schools,” says Kielburger. “It’s just as important as science or math.”

He’s not the only one who believes that; Microsoft chairman Bill Gates, renowned for giving away millions through his foundation, and Amway are helping sponsor the event. Over the years, We Day has attracted respected leaders including former Russian president Mikhail Gorbachev and the Dalai Lama to educate the children about the importance of service, and of providing help to those in need.

For Caleb Dawson, hearing Kielburger speak at his school inspired him to act. It’s not that his generation is a bunch of slackers, he says; it’s just that they’re not sure how to get involved. Once Kielburger laid out a framework, the kids were happy to help their community and start thinking about how to make an impact on the world beyond, one hashtag at a time.

This is amazing . Really amazing to see the teenagers nowadays to be so inspiring themselves . They are starting to outgrow what the politicians do . This is like a proof that you don't have to be in a particular position to change the world . You just gotta have the burning desire to make a difference , and belief that you can .